What is it about the Golden Gate Bridge, anyway? It's not the longest suspension bridge in the world anymore, or the tallest. It never was the busiest.

But it's a star, the way Bacall and Monroe were stars. The way Scarlett Johansson is a star today, and that lovely woman you met at a party isn't; the way Angela Lansbury is a star and your Aunt Lizzie is just a really nice 75-year-old lady.

The Golden Gate Bridge has everything: good looks, a gorgeous setting, a distinct color, a famous city on one side and steep, rolling hills on the other. It has style and sweeping curves. It appears and disappears in the fog, it has myths and legends and, sometimes, a fatal attraction.

The Caen Files: The Greatest Bridge Ever Built - A happy birthday message for the Golden Gate Bridge from the late Chronicle great Herb Caen.

Media: San Francisco Chronicle

"A necklace of surprising beauty," Chronicle reporter Willis O'Brien called it on the day it opened 75 years ago this month. "A masterpiece," John van der Zee called it in "The Gate," a book that appeared on the bridge's 50th birthday in 1987. "I believe it is America's Parthenon," he said more recently.

"It was pretty spectacular," said Martha Furman, who was 10 years old when she walked across it on opening day, May 27, 1937, and has remembered that walk ever since. She lives in Southern California now but is thinking about the bridge's 75th anniversary. "I might come up and walk across again," she said.

Robert David has worked for the Golden Gate Bridge district for 39 years. He is both a photographer and an architect, and has been everywhere on the bridge - from top to bottom.

The secret of what makes the Golden Gate special, he thinks, is all in the proportions of the bridge and the geometry that holds it up. Its design, he says, draws the eye.

One way to see the bridge's unique character is to compare it with its slightly older neighbor, the Bay Bridge. The Golden Gate's towers are much higher - 746 feet, compared with 526 feet for the Bay Bridge. Its roadway is placed at one-third of the height of the towers; on the Bay Bridge, the road cuts the towers in half.

The result, wrote Donald MacDonald, an architect who worked on both bridges, is "an aesthetically pleasing imbalance and sense of airiness - which the Bay Bridge ... lacked."

David goes further. Compared with the Golden Gate, he says, the Bay Bridge looks like a man wearing his pants too high.

The Golden Gate's towers also are stepped - they grow more slender as they grow taller, making them appear even higher than they really are.

Then there is the color.

Most bridges are painted a workmanlike green, silver or gray. The Golden Gate is vivid International Orange, a version of the original red lead primer applied to the steel when it first arrived from Pennsylvania mills. Consulting architect Irving Morrow, who hiked all over the Marin hills as a boy, wanted a bridge painted to fit the site where hills, water and fog mixed. He wanted "a red, earthy color ... admirable for enhancing the scale."

All of this, MacDonald says, "made the bridge a piece of art. There is nothing like it in the world."

To begin, there is the strait at the entrance to San Francisco Bay. Just over a mile wide at its narrowest point and more than 300 feet deep, the strait is formidable in itself. The Spanish called it La Boca de Puerto de San Francisco, but when the Americans came in 1846, it got a new name. "I named it Chrysopolae, or Golden Gate," wrote John C. Fremont, adventurer and U.S. Army officer, "for the same reason that the harbor of Byzantium was called Chrysoceras, or Golden Horn."

The Golden Horn, an inlet at what is now Istanbul, was the crossroads of the Old World, where East met West. Golden Gate was the perfect name.

An impossible project

It was impossible to build a bridge across the Golden Gate with the technology of the 19th century. But in the 20th century, the American century, bridging the Golden Gate seemed possible.

Joseph Baermann Strauss, a Chicago bridge builder, had constructed the Fourth Street drawbridge across Channel Creek in San Francisco in 1916; it still stands not far from AT&T Park. By the 1920s, Strauss had begun thinking about a bridge across the Gate.

His first design, in 1921, was for a combination cantilever and suspension bridge with towers nearly 800 feet high. It was amazingly ugly, but it was an idea, and Strauss was convinced it could be built.

In "The Gate," van der Zee points out that Strauss was not an engineer. "He was the drawbridge king," van der Zee said recently, "but not an engineer of any kind."

He was, however, a visionary, a promoter, an organizer and a master salesman. Historian Kevin Starr, in his 2010 book "Golden Gate," compares Strauss to P.T. Barnum and the Wizard of Oz.

Strauss made his first talk promoting a Golden Gate bridge at a Sausalito City Council meeting in 1922. Mayor James Madden recalled the event years later. At first it was a tough sell. Strauss, Mayor Madden would say, was "the world's worst speaker."

But Strauss got better and better, and his idea caught on. The 1920s were the flowering of the age of the automobile, and by the end of the decade thousands of cars overwhelmed the Marin ferry systems.

There was plenty of opposition to the bridge: particularly from the Southern Pacific Co., which had a transportation monopoly in the North Bay; from old-line conservatives; even from the Sierra Club, which worried that a bridge would destroy the beauty of the Golden Gate.

But the idea had power behind it. Bridge advocates circulated new drawings. The new design looked very much like the bridge we see now. It was stunning, and the idea of such a bridge fired the imagination. In 1930, at the beginning of the Great Depression, people in the new six-county Golden Gate Bridge and Highway District voted by a 3-to-1 margin for a $35 million bond issue, a major sum at the time.

An engineering dream team

Strauss assembled a matchless team to design and build the bridge: consulting engineers Charles Ellis, a professor at the University of Illinois; Leon Moisseiff, a designer and theoretician; and Othmar Ammann, a Swiss-born structural engineer who had built the George Washington Bridge in New York. There was also Charles Derleth, dean of the college of engineering at UC Berkeley; Andrew Lawson, a geologist and seismic expert; and two architects: John Elberson and Irving Morrow.

Strauss held the title of chief engineer, but others were responsible for the design. Ellis, in particular, did all the mathematical calculations that made the bridge possible. "The look, the heart of the bridge is his design," van der Zee said. "It all comes from him."

But Strauss would fire Ellis before his work on the bridge was complete. So Strauss got the lion's share of the credit and a statue at the San Francisco end. Ellis' name does not appear on the bridge. Clifford Paine took over as his No. 2 man.

Construction began in January 1933 and the bridge opened in May 1937, four years and four months later. There were 1,200,000 rivets, 80,000 miles of spliced wire, 254 steel suspender ropes connecting the cables with the deck, and a single, slightly arching span - 4,200 feet between the towers.

It was dangerous and exacting work - 11 men were killed building the Golden Gate Bridge, 10 in a single accident in February 1937.

The men who built it knew it best: "The bridge was outstanding and far above anything else," said Charles Kring, superintendent of cable spinning. "Everybody who worked on that bridge thought it was special," said Evan "Slim" Lambert. "I thought it was an honor to be able to work on something like that," said John Urban, an ironworker, " 'cause it's gonna be there a long time."

The bridge opened May 27, 1937, and 200,000 walked across. "The old town went nuts ..." Willis O'Brien wrote in The Chronicle. "It stood on its head. It walked on its hands. It threw its hat in the air."

Strauss offered a poem: "At last, the mighty task is done," it began.

Not long afterward, the Golden Gate Bridge became a symbol - and not always a symbol of success. The first known suicide came in August 1937, not three months after the bridge opened. At least 1,500 others have followed.

It also became the symbol of San Francisco, the way the old Ferry Building had been before it. Then a symbol of the West. And then of the country itself, almost like the Statue of Liberty.

During World War II, more than 1.5 million men and women sailed beneath the Golden Gate on warships and troopships. More soldiers, sailors and Marines followed in the Korean War, the Cold War and Vietnam. For many service members , the Golden Gate Bridge was the last sight of home. Some never saw it again.

Dick Fontaine was a soldier, returning on a troopship after a long voyage from Korea. It was just at twilight and as the ship passed under the Golden Gate Bridge, the soldiers began to cheer, from the bow of the ship to the stern. They threw their caps in the water, and Fontaine remembers seeing hundreds of hats, floating in the ship's wake.

Why did they do that? It was simple, he said.

"When that ship went under the bridge, the long, lousy trip was over, and Korea was over, the Army was over, all that stuff was over. We were home."